Show horses almost universally have their tails placed in a tail set. The set projects the base of the tail away from the horse's rear quarters at the esthetically pleasing angle generally observed with such animals. In particular, American Saddlebred Horses and Tennessee Walking Horses wear this cosmetic apparatus.
Many horses confined in stables also have their tails carried by tail sets. This arrangement prevents self-inflicted damage that would result from the horses swinging their tails against the sides of their stalls.
To accomodate the tail set, a horse may undergo the severing of the tendons and ligaments at the base of his tail. As a result, the horse no longer fights the tail set, which then completely determines the position of the tail.
The tail, while in a tail set, however, becomes prone to other types of damage. The usual movement of the horse may bring the tail into contact with his stall's walls. The resulting damage may include broken tail bones and abrasions involving hairs pulled out of the tail. Also the tail may catch over any extending rail or even the lower half of the stall's Dutch door, causing further injuries. Once caught, horses may slip out of the tail set, further injuring their tails.
To lessen the incidence of such injuries, some stables install tailboards to keep the horse's rear quarters away from the wall. Located at a height near the middle of the horse's rear legs, the tailboards simply prevent the rearward motion of the horse that can bring his tail into contact with the stall's perimeter.
However, not all stalls include such tailboards. Thus, when a horse travels to shows, for example, so assurance exists that his temporary lodgings will include the protective device for his safety and comfort.
Furthermore, the tailboards, at times, merely relocate the focus of the injuries. The horse's legs, rather than his tail may suffer damage.